3Z0 


The  Origin  and  Development 
the  Pycnidium 


v 


FORREST  ELLWOOD  KEMPTON 


Reprinted  for  private  circulation  from 
The  Botanical  Gazette,  Vol.  LXVIII,  No.  4,  October  1919 
Chicago,  Illinois 


The  Origin  and  Development  of 
the  Pycnidium 

ItrYESSlTT  Of  mm  UBHARY 


jAN  2 8 1920 


FORREST  ELLWOOD  KEMPTON 


B.S.  Earl  ham  College , igo6 
M.S.  University  of  Wisconsin,  igij 


THESIS 

SUBMITTED  IN  PARTIAL  FULFILLMENT  OF  THE  REQUIREMENTS  FOR  THE  DEGREE 
OF  DOCTOR  OF  PHILOSOPHY  IN  BOTANY  IN  THE  GRADUATE 
SCHOOL  OF  THE  UNIVERSITY  OF  ILLINOIS 
1918 


Reprinted  from  the  Botanical  Gazette,  Vol.  68,  No.  4,  Pp.  233-262, 
October  1919,  Chicago,  Illinois 


CONTENTS 


PAGE 

I.  Introduction 233 

II.  Methods 235 

III.  Genera  and  Species  Studied 236 

1.  Phoma 236 

2.  Macrophoma 238 

3.  Sphaeronaema 239 

4.  Sphaeropsis 240 

5.  Coniothyrium 241 

6.  Septoria 242 

7.  SphaeronaemeUa 243 

8.  Gloeosporium 244 

9.  Colletotrichum 244 

10.  Pestalozzia 245 

11.  Patellina 247 

12.  Volutella 248 

13.  Epicoccum 249 

14.  Meliola  (?)  . 250 

IV.  Discussion 250 

Table  I 251 

Table  II  253 

V.  Summary 254 

Acknowledgments 254 

References 255 

Plates  and  Explanation  of 257 

Vita  of  the  Author 262 

s 


11 


5S9.  £3 
KSZo 


VOLUME  LXVIII  NUMBER  4 

h 

^ THE 

Botanical  Gazette 


OCTOCER  ig iq 


ORIGIN  AND  DEVELOPMENT  OF  THE  PYCNIDIUM 


F.  E.  Kempton 
(with  plates  xvii-xxii) 


Introduction 


o 


S 


§ 


The  Ascomycetes  have  been  the  subject  of  repeated  investiga- 
tions, especially  in  regard  to  the  morphology  of  the  perithecium 
and  the  cytology  and  sexuality  of  the  ascigerous.  stage.  The 
conidial  stages,  placed  in  the  Fungi  Imperfecti  in  the  absence  of 
knowledge  of  their  ascigerous  stages,  of  necessity  are  classified 
on  a basis  of  the  morphology  of  the  conidia-bearing  structures. 
For  this  reason,  and  because  the  pycnidia  are  said  sometimes  to 
develop  directly  into  perithecia,  extension  of  our  knowledge  of  the 
morphology  of  such  conidiiferous  structures  as  the  pycnidium  and 
the  acervulus  is  highly  desirable. 

The  references  in  literature  to  the  development  of  the  pycnidium 
are,  for  the  most  part,  merely  incidental,  and  studies  directly 
devoted  to  the  subject  are  few.  As  early  as  1876  Bauke  (5) 
described  what  he  considered  as  3 methods  of  pycnidial  devel- 
opment, without  giving  names  to  them.  In  1884,  however, 
DeBaby  (9)  distinguished  2 main  methods  of  development, 
which  he  designated  as  ‘,‘symphogenous”  and  “meristogenous”: 
“symphogenous”  when  the  pycnidial  primordium  arises  through 
the  interweaving  of  young  hyphal  branches  to  form  a network  that 
is  at  first  loosely  woven,  but  later  becomes  compact  and  knotlike ; 


233 


234 


BOTANICAL  GAZETTE 


[OCTOBER 


“ meristogenous  ” when  the  primordium  arises  from  a single 
hyphal  cell  or  a group  of  adjacent  cells  of  a single  hypha  by  con- 
tinued cross  and  longitudinal  division.  In  the  latter,  branches  from 
neighboring  cells  or  from  the  mass  itself  may  share.  A number  of 
variations  of  these  2 methods  have  been  described.  Classification 
of  the  pycnidial  developments  described  by  Bauke  according  to  the 
methods  distinguished  by  DeBary  places  Cucurbitaria  as  meris- 
togenous, Diplodia  as  symphogenous,  and  Pleospora  polytricha  as  a 
combination  of  the  two. 

Zope  (52)  in  1890  mentioned  3 types  of  pycnidial  development  : 
“Hyphenfrucht,”  “Gewebefrucht,”  and  “Knauelfrucht.”  The 
“Hyphenfrucht”  comprises  those  in  which  development  proceeds 
from  a single  hyphal  cell  which  by  dividing  and  swelling  forms  a 
quadrant,  from  which  with  the  aid  of  2 or  3 neighboring  cells  a 
primordium  is  formed.  By  “ Gewebefrucht ” is  designated  those 
instances  in  which  a tissue  mass  is  formed.  This  mass  may  develop 
in  either  of  2 ways:  by  neighboring  cells  of  a hypha  becoming 
septate,  swelling,  dividing,  becoming  more  rounded,  while  short 
dividing  hyphae  either  from  the  mass  or  from  neighboring  cells 
of  the  hypha  share  in  the  formation;  or  in  a like  manner  it  may  be 
formed  from  cells  of  2 or  more  contiguous  hyphae.  The  “ Knauel- 
frucht ” develops  a primordium  from  1 or  more  short  hyphal 
branches  which  coil  spirally,  branch,  and  interweave  into  a knot 
which  later  develops  into  the  pycnidium.  The  “Hyphenfrucht” 
and  “Gewebefrucht”  are  clearly  variations  of  the  meristogenous 
method  of  development  of  DeBary.  The  other,  “Knauelfrucht,” 
is  symphogenous. 

In  addition  to  these  should  be  mentioned  the  “sporopycnidium” 
of  von  Tavel  (46),  referred  to  also  by  Planchon  (29)  and  Schnegg 
(33).  This  pycnidium  arises  meristogenously,  according  to  von 
Tavel,  representing  the  most  extreme  case  of  meristogenous 
development.  A single  spore  in  the  presence  of  abundant  food 
germinates  and  grows  a short  mycelium;  then  by  division  and 
growth  becomes  a pycnidium.  Reddick  (31)  notes  that  pycno- 
sclerotia  may  be  found  in  Guignardia.  These  bodies  arise  as 
pycnidia,  produce  pycnidiospores,  and  later  function  as  perithecia, 
producing  asci  and  ascospores. 


1919] 


KEMP  TON — PYCNIDIUM 


235 


Although  in  many  instances  the  fungi  were  not  studied  primarily 
as  to  their  pycnidial  development,  and  such  information  as  was 
collected  regarding  this  was  incidental,  according  to  the  figures  and 
descriptions  given  the  following  belong  to  the  meristogenous  group 
of  DeBary:  Pleospora  (Gibelli  and  Grifeini  17;  Bauke  5), 
Cucurbitaria  (Eidam  14;  Bauke  5),  Pycnis  (Brefeld  6),  Fumago 
(Tulasne  43;  Zopf  53;  Schostakowitsch  34),  Sphaeronaema 
(Halsted  and  Fairchild  18),  pycnidium  with  Teichospora 
(Nichols  27),  Phyllosticta  with  Alternaria  (Planchon  29), 
Sphaeropsis  and  Coniothyrium  (Potebnia  30),  Chaetophoma 
(Arnaud  3),  Phoma  (Reddick  31;  Mercer  26;  Schnegg  33), 
Endothia  (Anderson  i).  As  symphogenous  may  be  classed: 
Cicinnobolus  (DeBary  8),  Fumago  (Tulasne  43;  Zopf  52), 
Diplodia  (Bauke  5;  Van  der  Bijl  44),  Graphiola  (Fischer  15), 
Cystispora  (von  Tavel  46),  Render sonia  (Voges  45;  Wolf  51), 
pycnidium  with  Sphaerella  (Higgins  21),  Sphaeropsis  (Hesler  19), 
Septoria  (Levin  25).  A few  of  the  species  have  both  types  of 
development. 

The  present  investigation  is  an  endeavor  to  extend  our  knowl- 
edge of  the  very  early  stages  in  the  development  of  the  pycnidium 
and  kindred  structures. 

Methods 

For  the  present  study,  the  fungi  were  either  isolated  from  their 
hosts  or  cultures  were  procured  from  various  sources  as  noted. 
Corn  meal  agar  (35)  was  used  because  it  gave  an  abundant  growth, 
and  its  transparency  facilitated  the  study  of  even  the  youngest 
stages.  Other  media  were  used  in  a few  instances  for  comparison. 
Cultures  for  study  were  grown  in  Petri  dishes,  at  room  temperature 
(3:5— 370  C.).  Transfers  were  made  by  lifting  hyphae  or  spores 
from  pure  cultures  to  the  poured  agar  in  Petri  dishes.  Drop  cul- 
tures of  melted  agar  were  made  by  the  use  of  sterile  pipettes.  In 
some  cases  the  drop  of  agar  was  inoculated  with  spores  as  for  dilu- 
tion plating.  In  others,  each  drop  was  inoculated  by  transfer. 
These  drop  cultures  served  well  for  study  of  early  stages  of  develop- 
ment, but  seldom  produced  mature  conidiiferous  structures. 

Disks  of  agar  containing  young  pycnidia  were  removed  from 
Petri  dish  cultures,  placed  on  cover  glasses,  and  inverted  on 


236 


BOTANICAL  GAZETTE 


[OCTOBER 


Van  Tieghem  rings  in  order  to  follow  further  the  development  of 
the  pycnidia.  Growth  in  Petri  dishes  was  observed  periodically, 
the  intervals  depending  upon  the  rate  of  growth  of  the  organism. 
Pycnidia  of  each  species  were  kept  under  observation  during  then- 
entire  period  of  early  development.  For  close  detailed  study  and 
for  drawing,  mounts  were  made  by  removing  from  Petri  dish 
cultures  small  squares  of  agar  containing  pycnidia  in  various  stages 
of  development,  mounting  them  either  in  water  for  immediate 
study,  or  in  glycerine  for  later  study.  Material  from  test  tube 
cultures  was  teased  out  and  studied  for  comparison  and  verifica- 
tion of  many  points. 

Following  the  usage  of  earlier  writers,  DeBary  (9),  Bauke  (5), 
Zopf  (52),  and  von  Tavel  (46),  the  word  primordium  is  used 
throughout  this  paper  to  designate  a group  of  cells  that  have  become 
so  differentiated  that  it  is  clearly  evident  that  from  them  a pycnidial 
or  similar  structure  will  arise. 

Genera  and  species  studied 

Phoma  (Fries)  Desmazieres 

Phoma  herbarum  West;  isolated  from  its  host,  Polygonum 
hydropiper  L.,  at  Urbana,  Illinois,  July  8,  1916. 

Pycnidia  are  produced  in  cultures  in  moderate  abundance. 
All  stages  of  development,  from  the  mature  pycnidia  on  older 
mycelium  to  beginning  stages  on  the  younger  mycelium,  can  be 
observed  even  in  a small  sector  of  a Petri  dish  culture.  Develop- 
ment proceeds  typically  from  a single  cell  of  a hypha.  This  cell 
divides  both  transversely  and  diagonally  (fig.  1)  into  a few  cells 
which  swell  and  enlarge.  These  cells  by  continued  swelling  and 
dividing  form  an  irregular  mass  with  very  few  or  no  hyphal 
branches.  This  mass  shows  distinctly  its  origin  from  a single  hypha 
(figs.  1-3).  As  the  mass  continues  to  enlarge,  one  side  protrudes 
slightly  as  a short  rostrum  which  becomes  lighter  in  color 
(fig.  4).  This  is  the  primordium  which  later  becomes  a pear- 
shaped  pycnidium  with  an  ostiole  from  which  spores  are 
discharged  (fig.  5).  The  development  is  a typically  simple  meris- 
togenous  one. 


1919] 


KEMPTON — PYCNIDIUM 


237 


Phoma  pirina  (Fries)  Cooke;  isolated  at  Urbana,  Illinois,  May  10, 
1916,  from  dead  twigs  of  Pyrus  communis  L.  from  Savoy,  Illinois. 

This  fungus  produces  abundant  small  pycnidia  60-1 20  /jl  in 
diameter,  at  first  closed  but  later  with  an  ostiole  20-30  n wide. 
The  spores  vary  in  size  from  5X3  to  10X4  A few  cells  of  the 
hypha  swell,  divide  both  crosswise  and  diagonally,  swell,  and  divide 
again  (figs.  6,  7).  This  small  mass  continues  to  enlarge  by  cell 
division,  and  a few  hyphal  branches  bud  out  from  it  (fig.  8).  By 
continued  development  an  irregular  mass  (fig.  9)  is  formed,  which  is 
the  primordium  of  the  pycnidium.  In  a few  cases  closely  lying 
hyphae  may  take  part  in  the  formation  (figs.  10-13),  but  the 
typical  method  of  development  is  the  simple  meristogenous  one 
from  a few  cells  of  a single  hypha. 

Phoma  destructiva  Plowr.;  isolated  at  Urbana  from  fruits  of 
tomato  (Ly coper sicon  esculentum  Mill.)  in  September  1915.  In 
all  respects  the  disease  and  the  fungus  agreed  with  the  one  described 
by  Miss  Jamieson  (22) . 

The  pycnidial  primordium  usually  arises  meristogenously.  In 
most  cases  a single  hypha  gives  rise  to  the  primordium  (figs.  14-17) ; 
in  other  cases  2 or  more  hyphae  share  in  its  formation  (figs.  18,  19, 
22).  In  either  case  adjacent  cells  swell  and  divide  crosswise  and 
diagonally  until  a rounded  or  elongated  mass  is  formed,  slightly 
darker  in  color  than  the  mycelium.  The  former  (fig.  15)  is  the 
simple  type  of  meristogenous  development. 

Phoma , species  indet.;  isolated  from  stems  of  clover  ( Trifolium 
pratense  L.)  at  Urbana,  Illinois,  in  July  1916. 

Development  takes  place  in  a simple  meristogenous  manner. 
One  hypha  only  is  involved  in  the  formation  of  the  primordium 
(figs.  23-27).  Short  hyphal  threads  sometimes  branch  from  the 
mass.  The  cells  are  usually  large  and  swell  into  a rounded  shape. 
The  mass  develops  more  rapidly  at  one  end  than  at  the  other,  so 
that  the  young  pycnidium  is  slightly  conical. 

Phoma , species  indet.;  isolated  from  a berry  of  the  Concord 
variety  of  grape  (Vitis  labruscaL.),  from  a vineyard  near  Collins- 
ville, Illinois,  September  1917. 

A portion  of  the  culture  seen  under  the  high  power  of  the  micro- 
scope showed  a very  characteristic  arrangement  of  hyphae  and  of 


238 


BOTANICAL  GAZETTE 


[OCTOBER 


pycnidia  in  various  stages  of  development  (figs.  28-33).  The 
simple  meristogenous  development  of  the  primordium  is  similar 
to  that  described  for  Phoma  herbarum  West  (figs.  1-5). 

Phoma  cichorii  Passr.;  isolated  from  Phlox  divaricata  L.  by 
Mrs.  Esther  Young  True,  at  Urbana,  Illinois,  November  1917. 

A few  adjacent  cells  of  a single  hypha  or  of  a number  of  con- 
tiguous hyphal  strands  divide  into  short  cells  (figs.  34,  35).  By 
budding  and  swelling,  short  hyphal  branches  arise,  the  cells  of 
which  swell  and  divide  (fig.  36).  The  cells  of  the  mother  strand 
or  strands  also  enlarge  and  divide.  The  component  hyphae 
anastomose,  forming  a pseudoparenchymatous,  irregularly  rounded 
mass.  This'  mass  develops  into  the  pycnidium.  The  develop- 
ment of  this  fungus  differs  from  that  described  for  the  other  species 
in  that,  where  only  a single  strand  is  involved,  the  mode  is  simple 
meristogenous  with  the  original  cells  and  their  budding  branches 
anastomosing  to  form  the  mass  (fig.  36).  In  instances  where  2 or 
more  strands  are  involved  (fig.  37),  there  has  been  a similar  division, 
swelling,  and  branching  in  each  strand,  but  the  whole  has  been 
united  into  a single  primordium  as  described  for  Phoma  destructiva 
(fig.  22).  This  mode  is  compound  meristogenous. 

Macrophoma  (Sacc.)  Berl.  and  Vogl. 

Macrophoma  citrulli  (B.  and  C.)  Berl.  and  Vogl.;  isolated  by 
Dr.  J.  A.  Elliott  from  a cantaloupe  ( Cucumis  melo  L.)  leaf  pro- 
cured from  Alabama  in  the  autumn  of  1915. 

Young  pycnidia  and  small  sclerotia  form  in  abundance,  soon 
rendering  the  culture  dark  brown  or  black.  Usually  a single  cell 
in  a hypha  becomes  slightly  swollen.  It  then  divides  into  2 short 
cells  (fig.  38).  These  cells  in  turn  divide  by  cross,  longitudinal,  and 
diagonal  walls  (figs.  39,  40).  The  swelling  continues  until  the  body 
becomes  a rounded  or  oblong  mass  much  darker  than  the  light 
brown  mycelium  (figs.  46,  47).  The  cells  immediately  adjacent 
to  the  dividing  mass  may  divide  into  short  cells  and  send  out  hyphal 
branches  (figs.  42-44).  The  outer  cells  of  the  mass  may  also  send 
out  branching  hyphae.  The  hyphae  from  all  these  sources  form 
a network  about  the  enlarging  mass.  Sometimes  the  hyphal 
branches  fuse  with  the  mass,  and  in  other  cases  they  appear  to 


KEMPTON — PYCNIDIUM 


239 


1919] 

have  no  part  in  its  formation.  The  body  thus  developed  is  the 
primordium  from  which  the  pycnidium  arises.  It  continues  to 
enlarge,  becomes  pear-shaped,  forms  an  ostiole,  and  develops 
spores.  This  mode  of  development  is  meristogenous,  with  a slight 
modification  in  that  short  hyphal  branches  either  fuse  with  or 
form  an  envelope  about  the  primordium. 

Less  frequently  a second  method  appears,  in  which  short 
branches  from  main  mycelial  strands  direct  themselves  toward  a 
point.  There  these  branches  interweave,  swell,  and  divide  to 
form  a network  (fig.  48).  This  network  is  at  other  times  formed 
by  the  looping  back  or  snarling  of  hyphal  branches.  The  tangle 
enlarges,  becomes  more  tightly  woven,  then  the  cells  divide,  swell, 
and  anastomose  to  form  a pseudoparenchymatous  mass  (fig.  49). 
This  method  is  symphogenous.  This  species  gives  rise  to  both 
meristogenous  and  symphogenous  developments. 

The  pycnidia  of  the  species  studied  in  the  genera  Phoma  and 
Macrophoma  indicate  that  both  meristogenous  and  symphogenous 
methods  of  development  may  be  found.  These  species  present  in 
the  main  the  simple  meristogenous  mode  in  which  a few  cells  of  a 
single  hypha  take  part  (figs.  1,  6,  15,  23,  29,  38,  44);  also  a slight 
variation  of  the  simple  development  in  which  hyphal  branches 
both  from  the  dividing  celJs  and  from  other  cells  of  the  mother 
hypha  form  a network  about  the  original  cells  taking  part  in  the 
development  (figs.  36,  39,  47).  The  compound  meristogenous 
development  is  that  in  which  2 or  more  main  hyphae,  lying  parallel 
or  crossing,  begin  to  divide  into  short  cells  at  a point  of  contact, 
swelling  and  dividing  to  form  a primordium  (figs.  18,  22,  37). 
A few  adjacent  cells  of  each  hypha  and  some  surrounding  branches 
take  part  in  this  type  of  development. 

Sphaeronaema  Fries 

Sphaeronaema  fimbriatum  (E.  and  H.)  Sacc.;  procured  from 
Dr.  Byron  D.  Halsted,  October  1916. 

Halsted  and  Fairchild  (18)  report  and  figure  the  develop- 
ment of  the  pycnidium  of  Ceratocystis  fimbriata  as  follows: 

In  its  initial  stages  the  pycnidium  arises  as  the  swollen  and  curled  or 
twisted  tip  of  a vegetative  hypha,  or  as  a twist  or  knot  in  a sporophore  between 


240 


BOTANICAL  GAZETTE 


[OCTOBER 


the  conidium  and  its  point  of  union  with  the  main  hypha.  Although  observed 
to  be  present  in  numerous  cases,  no  anastomosing  of  different  hyphae  branches 
seems  necessary.  Almost  simultaneously  with  the  first  curving  of  the  hypha 
tip  side  branches  arise,  which,  by  their  growth  and  formation  of  septa,  form 
the  coarsely  cellular  membranous  wall  of  the  pycnidium. 

Single  mountings  from  plate  cultures  gave  all  stages  of  develop- 
ment verifying  this  description.  The  usual  development  was  the 
twisting,  budding,  branching,  and  enlarging  by  cell  division  of  single 
twisted  hyphal  branches  (figs.  50-52).  This  is  a variation  of  the 
meristogenous  development. 

Sphaeropsis  Leveille 

Sphaeropsis  malorum  Pk.;  isolated  from  apple  fruits  ( Pyrus 
malus  L.)  from  Centerville,  Indiana,  in  October  1916. 

Hesler  (19)  gives  the  development  of  the  pycnidium  of 
Physalospora  cydoniae  Arnaud  in  agar  cultures  as  follows : 

The  dense  pseudoparenchyma  of  the  maturer  fruit  bodies  suggests  meri- 
stematic  divisions,  but  apparently  the  structure,  for  the  most  part,  arises 
symphogenetically.  In  agar  cultures  a group  of  threads  may  be  observed  to 
be  directed  toward  a common  point  where  the  pycnidium  is  to  be  formed. 
Here  the  hyphae  are  composed  of  cells  6-7  /x  broad,  their  length  varying  from 
20  to  70  /x,  always  longer  than  broad.  In  the  region  where  the  pycnidium  is 
to  be  developed,  the  cells  become  noticeably  shorter  by  the  laying  down  of 
new  walls;  the  cells  also  increase  in  diameter  by  growth,  and  the  hyphae 
increase  their  numbers  by  branching.  The  interspaces  found  in  the  earlier 
stages  are  filled  by  the  growing  in  of  these  branches  and  by  a budding-like 
action  of  the  hyphal  cells  bordering  the  space. 

Among  my  own  notes  upon  Sphaeropsis  malorum  Pk.,  made 
before  the  appearance  of  this  description,  is  an  account  of  the 
development  of  the  primordium  which  it  seems  worth  while  to 
give  here. 

The  pycnidial  primordium  of  this  species  is  formed  usually 
according  to  the  method  designated  by  DeBary  as  symphogenous. 
A number  of  hyphal  branches  interweave  near  their  ends  (fig.  53) ; 
these  in  turn  branch  and  the  branches  also  interweave  (figs.  54, 
55).  The  central  portion  becomes  a tightly  woven  mass.  The 
whole  continues  to  enlarge  until  a spherical  mass  is  formed,  which 
develops  into  a pycnidium.  Most  of  these  primordia  form  deeply 


1919] 


KEMPTON — PYCNIDIUM 


241 


imbedded  in  the  agar,  although  a few  develop  on  or  near  the  sur- 
face. Those  developing  imbedded  in  the  agar  are  smooth,  while 
those  on  the  surface  have  a fuzzy  appearance.  A very  few  pycnidia 
form  by  the  compound  meristogenous  method  described  for  Phoma . 
These  usually  form  2 or  more  contiguous  hyphae  in  which  a few 
adjacent  cells  divide,  swell,  continue  to  divide,  and  enlarge  until 
a primordium  similar  to  the  one  described  is  formed. 

Sphaeropsis  citricola  McAlpine;  isolated  at  Urbana,  Illinois, 
January  1916,  from  a kumquat  fruit  (. Fortunella  margarita  Swingle) 
from  Lake  City,  Florida.  The  condition  produced  on  the  rind  of 
the  fruit  was  that  of  a very  black  carbonaceous  spotting  which 
finally  spread  over  the  whole  fruit. 

In  culture  a coarse  brown  mycelium  5-8  n in  diameter  is  pro- 
duced. Numerous  pycnidia  80-175  M in  diameter  develop  from 
primordia  each  of  which  arises  either  from  a single  cell  or  a few 
adjacent  cells  in  a single  hypha.  This  cell  or  group  of  cells  (figs.  56, 
57)  divides  by  cross  and  diagonal  walls  (figs.  58-61),  later  by  the 
addition  of  longitudinal  walls  to  form  a rounded  or  elongated  mass 
(figs.  62,  63)  which  is  slightly  darker  in  color  than  the  mycelium. 
This  mass  becomes  globose,  light  brown,  carbonaceous  and  reticu- 
lated, and  is  the  primordium.  Development  is  usually  simple 
meristogenous.  The  compound  meristogenous  mode  is  seldom 
found  (figs.  64-66).  From  pycnidia  developing  from  these  masses 
small  hyaline  spores  5-7  X 4-5  ju  exude. 

The  genus  Sphaeropsis  presents  a variation  of  the  symphogenous 
development  in  that  the  branches  interweave  near  their  ends  at  a 
point  some  distance  from  the  main  mycelial  strands  (fig.  53). 
It  also  shows  the  more  usual  symphogenous  type  (figs.  54,  55) 
described  for  Macrophoma  (figs.  48,  49).  Simple  meristogenous 
development  occurs  in  one  species.  The  compound  mode  seldom 
occurs  in  the  species  studied. 

Coniothyrium  Corda 

Coniothyrium  pyriana  (Sacc.)  Shel. ; pure  culture  isolated  from 
twigs  of  apple  ( Pyrus  malus  L.)  from  Savoy,  Illinois,  October  1916. 

A few  adjoining  cells  of  a main  hypha  become  slightly  swollen 
and  divide  into  short  cells  (figs.  67,  68).  These  cells  swell,  divide 


242 


BOTANICAL  GAZETTE 


[OCTOBER 


by  cross,  diagonal,  and  longitudinal  divisions,  and  continue  to 
swell  and  send  out  short  hyphal  branches  by  budding  (figs.  69,  70). 
This  body  increases  in  size,  becoming  darker  in  color.  Branches 
from  adjoining  cells  or  closely  lying  hyphae  may  interweave  with 
the  branches  from  the  mass,  at  length  forming  a primordium  (fig.  71). 
from  which  a pycnidium  develops.  Usually  this  primordium  arises 
from  a single  main  hypha,  but  occasionally  2 or  more  contiguous 
hyphae  are  included  in  its  formation.  The  mode  of  development 
is  meristogenous,  with  small  hyphal  branches  at  times  included  in 
the  formation.  Both  simple  and  compound  modes  are  found,  but 
the  compound  mode  seldom  occurs. 

Coniothyrium , species  indet.;  culture  procured  from  the  air 
of  the  laboratory  in  the  summer  of  1917  by  W.  S.  Beach. 

A few  adjacent  cells  in  a single  hypha  divide  into  shorter  cells. 
These  cells  branch  profusely  (fig.  72).  A few  of  the  cells  continue 
to  divide  and  swell,  and  the  branching  hyphae  divide  and  branch 
(fig.  73).  The  whole  becomes  a more  closely  formed  mass  (fig.  74) 
which  forms  a globose,  dark  brown,  finely  reticulated  primordium. 
From  this  the  pycnidium  develops.  The  mode  of  development  is 
simple  meristogenous. 

The  genus  Coniothyrium , so  far  as  studied,  presents  only  the 
meristogenous  development. 

Septoria  Fries 

Septoria  polygonorum  Desm. ; isolated  from  its  host  Polygonum 
persicaria  L.  at  Urbana,  Illinois,  July  1916. 

The  development  of  the  primordium  in  most  cases  is  by  the 
usual  meristogenous  method,  but  in  some  instances  it  is  atypical. 
Some  of  the  primordia  arise  from  a single  hypha,  1 or  2 cells  of 
which  divide  transversely  and  diagonally,  and,  swelling  slightly, 
continue  to  divide  (fig.  75).  Later  this  mass  develops  into  a 
globose,  finely  reticulated,  pale  brown  body.  In  some  instances 
the  compound  mode  appears  in  which  2 or  more  hyphae  are 
involved  in  the  formation  (fig.  76).  In  other  cases  primordia 
are  to  be  found  arising  from  a main  hyphal  strand  with  numerous 
branches  of  nearby  hyphae  intermingling  in  the  mass  (fig.  77). 
This  involves  both  the  meristogenous  and  the  symphogenous 


1919] 


KEMPTON — PYCNIDIUM 


243 


methods,  and  so  may  be  considered  a combination  of  the  two. 
The  principal  method  of  development  is  meristogenous. 

Septoria  scrophulariae  Pk.;  isolated  from  its  host  Scrophularia 
leper ella  Bicknell  by  Mr.  Walter  S.  Beach  during  the  summer  of 
1917. 

In  pure  culture  it  produces  a closed  sporing  body,  the  primor- 
dium  of  which  arises  either  from  a few  cells  of  a single  hypha  or 
from  2 or  3 closely  lying  hyphae  (figs.  78,  79).  These  primordial 
cells  divide,  swell,  and  continue  to  divide  to  form  a small  ball-like 
structure  which  later  develops  into  1 or  more  pycnidia.  They 
thus  arise  either  by  the  simple  or  compound  meristogenous  mode. 

Septoria  helianthi  E.  and  K.;  isolated  from  its  host  Helianthus 
grosseserratus  Mortens  by  Mr.  Walter  S.  Beach  in  the  summer  of 
1917  at  Urbana,  Illinois. 

Pycnidia  form  readily  in  culture.  A single  cell  or  a few  adjoin- 
ing cells  in  a hypha  become  slightly  swollen.  These  then  divide 
into  shorter  cells  which  swell  and  send  out  very  short  branches 
(fig.  80).  The  swelling  continues  until  a rounded  mass  is  formed, 
slightly  darker  in  color  than  the  pale  brown  mycelium  (fig.  81). 
The  body  thus  formed  becomes  almost  globose  in  shape.  The 
outer  portion  or  covering  becomes  membranous  with  a cellular 
appearance.  This  primordium  continues  to  enlarge,  and  becomes 
ovate  or  elliptical  in  shape.  The  development  is  simple  meristoge- 
nous, within  a single  strand  of  mycelium. 

The  genus  Septoria  can  hardly  be  judged  by  these  few  species, 
but  these,  with  those  reported  in  the  literature,  indicate  that  the 
2 main  methods  of  development,  namely,  meristogenous  and 
symphogenous,  and  even  a combination  of  these  two,  may  occur. 

Sphaeronaemella  Karst. 

Sphaeronaemella  fragariae  Stevens  and  Peterson;  procured 
from  Dr.  Alvah  Peterson,  Urbana,  Illinois. 

A few  cells  of  a single  hypha  divide,  producing  very  short  cells. 
These  bud  and  branch  profusely,  usually  in  one  direction,  into  short 
hyphae  (fig.  82).  These  branches  anastomose  (fig.  83),  twining 
about  in  a circular  manner.  They  then  divide  and  swell,  forming  a 
small  mass  which  usually  protrudes  from  one  side  of  the  main 


244 


BOTANICAL  GAZETTE 


[OCTOBER 


mycelial  strand  from  which  it  arises  (fig.  22).  The  body  thus 
formed  is  the  primordium  from  which  the  pycnidium  arises. 

In  the  genus  Sphaeronaemella  a striking  variation  of  the  meris- 
togenous  development  is  found.  A few  cells  of  a main  mycelial 
thread  begin  to  divide  as  in  the  simple  meristogenous  mode,  but 
short  hyphal  branches  arise  from  these,  usually  on  one  side,  curling 
and  twisting  about  each  other  to  form  a ball-like  mass.  In  some 
cases  this  mass  envelops  and  includes  the  main  hypha  (fig.  84). 

Gloeosporium  Desmazieres  and  Montaigne 

Gloeosporium  rufomaculans  (Berk.)  Thiim.;  isolated  from  fruit 
of  apple  (. Pyrus  malus  L.)  from  Neoga,  Illinois,  September  1917. 

The  primordium  of  the  acervulus  arises  from  a number  of  neigh- 
boring hyphae.  These  branch  into  short  hyphae  which  branch 
in  turn,  forming  a loosely  woven  network.  A spreading  tuft  arises 
from  this  loosely  woven  base  (fig.  87).  This  cushion  with  its  tuft 
of  short  hyphae  is  the  primordium.  It  usually  originates  sym- 
phogenously,  sometimes  meristogenously. 

Gloeosporium  musarum  C.  and  M.;  isolated  from  a banana 
( Musa  sapientum  L.)  from  the  Champaign  market,  July  28,  1916. 

Short  hyphal  branches  from  main  mycelial  strands  interweave 
near  their  ends.  Other  hyphae  intertwine  about  this  initial  portion. 
Some  branches  fold  or  loop  back  upon  themselves,  while  still  others 
branch  again.  The  cells  of  the  interwoven  mass  divide,  swell,  and 
branch  (fig.  88).  At  length  a cushion-like  base  is  formed.  This 
is  the  primordium  of  the  acervulus,  from  which  short  conidiophores 
arise  which  bear  conidia.  In  terms  of  pycnidial  development  it 
arises  symphogenously.  In  culture  this  fungus  bears  many  spores, 
either  sessile  or  upon  short  conidiophores  outside  of  acervuli, 
scattered  freely  upon  the  mycelium.  These  spores  appear  before 
the  formation  of  acervuli,  making  the  study  of  the  beginning  of 
acervuli  difficult. 


Colletotrichum  Corda 

Colletotrichum  lagenarium  (Pers.)  E.  and  H.;  isolated  from  a 
watermelon  ( Citrullus  vulgaris  Schrad.)  procured  on  the  Champaign 
market,  September  1917. 


1919] 


KEMPTON — PYCNIDIUM 


245 


The  primordia  of  the  acervuli  begin  their  formation  deeply 
imbedded  in  the  media,  even  near  the  bottom,  by  the  time  the  cul- 
ture is  4 cm.  in  diameter  and  no  more  than  4 or  5 days  old.  At 
this  age  no  conidia  have  developed  upon  the  short  conidiophores 
or  as  buds  from  cells  of  hyphae,  as  often  occurs  when  the  culture 
becomes  older.  The  primordia  arise  by  2 methods:  (1)  from  a few 
cells  of  a main  hypha  arise  a few  or  many  short  budlike  hyphae 
(figs.  89-92);  these  elongate,  intertwine,  and  branch  to  form  a 
cushion-like  base  from  which  very  short  conidiophores  arise; 
(2)  hyphal  branches  from  a few  neighboring  or  contiguous  mycelial 
strands  intertwine,  some  of  the  threads  forming  short  loops  which 
mass,  intertwine,  and  branch  (figs.  93-96),  forming  an  irregularly 
shaped,  loosely  made,  cushion-like  base  from  which  conidiophores 
arise  as  in  the  other  type.  Irregular  large  acervuli,  or  acervuli-like 
groups,  . bearing  numerous  conidia,  arise  in  this  latter  type. 
The  first  mentioned  type  may  be  considered  as  meristogenous, 
both  simple  and  compound  modes  appearing;  the  second  is 
symphogenous. 

The  genera  Gloeosporium  and  Collelotridmm  have  been  exten- 
sively studied  by  Shear  (36),  Stoneman  (42),  Southworth 
(38,  39),  Edgerton  (ii),  and  others.  Late  stages  of  development 
and  cross-sections  of  different  stages  have  been  figured  from  fixed 
material  in  host  tissues,  but  little  has  been  said  in  regard  to  the 
early  development  of  the  acervulus.  The  3 species  studied  give 
insight  only  into  the  origin  of  the  cushion-like  base  from  which  the 
acervulus  arises.  They  present  2 distinct  types,  the  simple  loosely 
woven  base  that  arises  from  a single  hypha  or  from  a few  contiguous 
hyphae,  and  the  more  complexly  interwoven  base  which  arises 
symphogenously. 

Pestalozzia  De  Notaris 

Pestalozzia  palmar um  Cke.;  pure  culture  procured  from  the 
Centralstelle  fur  Pilzkulturen,  Amsterdam,  Holland. 

A few  hyphae,  usually  2-6,  lying  side  by  side  form  a bed  in 
which  a few  cells  begin  to  divide  into  shorter  cells.  These  cells 
may  be  in  only  one  of  the  hyphae  (fig.  97 a),  or  they  may  be  con- 
tiguous cells  of  2 or  more  hyphae  (fig.  100).  These  cells  swell  and 
continue  to  divide  by  cross  and  longitudinal  walls,  at  length  forming 


246 


BOTANICAL  GAZETTE 


[OCTOBER 


a protruding  oval  or  obovate  body  (fig.  97 b)  which  is  the  primor- 
dium  of  the  pycnidium-like  body  which  later  forms.  This  primor- 
dium  arises  by  either  simple  (fig.  97 a)  or  compound  meristogenous 
(fig.  100)  development.  It  soon  becomes  globose  and  membranous, 
with  a cellular  outer  wall,  but  remains  light  of  color,  so  that  a few 
dark  spores  may  be  seen  within  (figs.  98,  99).  At  this  stage  the 
structure  is  to  all  appearances  a young  pycnidium  (fig.  101). 
Within  a few  days  the  top  breaks,  the  few  spores  already  formed 
are  extruded,  sometimes  rather  forcibly  (fig.  102),  and  the  cavity 
then  becomes  saucer-shaped.  Conidiophores  arise  in  profusion, 
and  many  spores  are  produced.  When  the  first  spores  are  noted 
the  body  is  a pycnidium,  if  observed  in  a later  stage  it  appears 
like  an  acervulus.  In  Pestalozzia  capiomanti  similar  facts  were 
noted  by  Bainier  and  Sartory  (4),  while  Leininger  (24)  in  his 
studies  of  P.  palmar um  speaks  of  these  bodies  as  pseudo- 
pycnidia. 

Pestalozzia  guepini  Desm. ; isolated  from  the  fruit  of  a kumquat 
(. Fortunella  margarita  Swingle)  from  Lake  City,  Florida,  January 
1916. 

A few  pycnidia  were  produced  in  plate  culture.  In  the  begin- 
ning stages  a number  of  branches  of  closely  lying  or  nearby  hyphae 
branch,  snarl,  and  intertwine  (figs.  103,  104).  Cells  within  the 
more  closely  twined  part  of  the  mass  swell  and  divide  by  continued 
cross  and  longitudinal  divisions  until  a rounded  mass  is  formed, 
which  is  the  primordium  of  the  pycnidium  (fig.  105).  This  primor- 
dium  arises  symphogenously.  The  development  of  the  final 
sporing  body  from  this  stage  is  very  similar  to  that  described  for 
Pestalozzia  palmarum. 

Pestalozzia , species  indet.;  isolated,  by  the  author  November 
1916,  from  leaves  of  peony  ( Paeonia  officinalis  Retz)  procured  by 
Dr.  H.  A.  Anderson  near  Crawfordsville,  Indiana. 

A good  growth  of  mycelium  and  numerous  sporing  bodies 
were  produced  in  plate  cultures.  The  mycelial  threads  are  slightly 
larger  than  those  of  other  species  of  Pestalozzia  studied.  Pycnidial 
primordia  arise  usually  by  the  compound  meristogenous  method 
(figs.  107,  108).  As  these  bodies  develop  from  the  pycnidial  stage 
to  the  open  type,  the  formation  of  spores  within  (fig.  109),  a 


KEMPTON — PYCNIDIUM 


247 


1919] 

breaking  open  of  the  pycnidium,  and  its  further  development  int 
what  appears  to  be  an  acervulus  may  be  seen. 

Pestalozzia , species  indet. ; pure  culture  procured  from 
Dr.  G.  P.  Clinton,  New  Haven,  Connecticut,  in  November  1916. 
It  had  been  isolated  from  dead  maple  (Acer)  bark  in  October  1910. 

This  Pestalozzia  was  the  most  vigorous  of  all  those  cultured. 
Sporing  bodies  were  produced  in  abundance.  Two  or  3 contiguous 
hyphae,  or  in  some  cases  as  many  as  10  or  12,  take  part  in  the  forma- 
tion of  the  primordium.  A few  cells  continue  to  swell  and  divide 
until  a small  mass  is  formed  (fig.  no).  They  branch  slightly 
fig.  iii)  until  a primordium  of  tissue-like  type  is  formed.  It  is 
of  compound  meristogenous  development,  especially  pronounced 
in  cases  where  10  or  more  hyphae  take  part.  The  young  pycnidia- 
like.  bodies  continue  to  develop,  produce  spores,  then  break  open 
(fig.  1 1 2)  and  change  into  the  acervulus  form  as  in  the  previous 
species  mentioned. 

In  Pestalozzia  a condition  is  found  that  is  quite  distinct  from 
any  other  acervulus-forming  fungus  studied,  in  that  it  first  pro- 
duces §a  sporing  body  which  morphologically  is  a pycnidium. 
These  pycnidia  arise  by  any  of  the  various  modes  previously 
described.  The  different  species  vary  in  the  manner  of  develop- 
ment, but  whatever  the  method  there  first  appears  a pycnidium 
which  later  breaks  open  and  becomes  acervulus-like. 

Patellina  Speg. 

Patellina  fragariae  Stevens  and  Peterson;  pure  cultures  pro- 
cured of  Dr.  A.  Peterson,  September  1916.  It  was  also  isolated 
from  strawberries  (Fragaria  chiloensis  Duschesne)  from  Center- 
ville, Indiana,  June  1916. 

This  fungus  forms  numerous  sporodochia  in  concentric  rings  in 
plate  cultures.  These  sporodochia  arise  in  2 rather  typical  ways. 
A few  cells  of  a hypha  divide  into  very  short  cells.  These  cells 
swell  and  bud,  producing  numerous  branches  in  some  cases  (fig.  1 1 5) , 
in  other  cases  a tuft  of  2 or  3 branches.  These  branches  elongate 
slightly  to  form  a pedicel  (fig.  116),  then  branch  at  the  tips  and 
radiate  to  form  a distinct  urnlike  body  (fig.  117),  within  which  a 
cushion  or  bed  forms  and  gives  rise  to  the  conidiophores.  The 


248 


BOTANICAL  GAZETTE 


[OCTOBER 


sporodochia  are  usually  produced  singly  by  a simple  meristogenous 
mode.  In  other  instances  sporogenous  areas  develop,  and  in  these 
1 or  2 cells,  in  each  of  the  closely  lying  hyphae,  branch  profusely 
(fig.  1 13).  Many  of  these  branches  unite  into  a mass  and,  without 
the  formation  of  a definite  pedicel  and  peridium  (fig.  114),  give 
rise  to  hundreds  of  conidiophores. 

Patellina , species  indet.;  from  a quince  ( Cydonia  vulgaris  L.) 
procured  on  the  Champaign  market,  November  1917. 

Strands  of  6-20  hyphae  are  formed,  and  at  some  definite  point 
within  the  strand  a few  adjacent  cells  branch;  thus  a tuft  of  a 
number  of  branches  is  formed  (fig.  1 18) . This  tuft  becomes  slightly 
larger  at  the  upper  end  by  continued  branching,  while  the  lower 
portion  constitutes  a pedicel  consisting  of  a few  large  branches, 
where  a few  hyphae  enter  into  its  formation.  A more  substantial 
closely  formed  pedicel  or  base  is  present  if  a larger  number  of  hyphal 
branches  are  concerned  in  its  origin  (figs.  118,  119).  The  upper 
half  or  less  becomes  cuplike,  and  the  outer  hyphae  curve  inward  as 
a superficial  covering,  while  within  conidiophores  and  conidia  are 
formed.  The  type  is  compound  meristogenous. 

In  Patellina  the  sporodochium  develops  in  a very  characteristic 
manner,  arising  by  the  meristogenous  method.  A single  isolated 
mycelial  thread  gives  rise  to  a very  simple  sporodochium.  If  a 
number  of  mycelial  strands  are  crowded  together,  each  branches 
characteristically,  and  the  branches  form  a sporodochium  of  the 
compound  type.  The  type  of  sporodochium  varies  with  the  type 
of  base  formed. 


Volutella  Tode 

Volutella  fructi  S.  and  H.;  procured  from  Mr.  Wilmer  G. 
Stover,  Ohio  State  University.  It  was  isolated  by  G.  C.  Meck- 
stroth  in  the  winter  of  1916  from  a fruit  of  apple  ( Pyrus  malus  L.) 
grown  in  western  Ohio. 

The  sporodochia  form  in  abundance  in  plate  cultures,  the 
primordium  arising  from  a main  hypha.  A definite  portion, 
1,  2,  or  3 cells  in  length,  takes  on  a brownish  color.  These  cells 
divide  and  some  of  them  branch,  usually  from  one  side  only  (figs.  120, 


KEMPTON — PYCNIDIUM 


249 


1919] 

124),  forming  a small  tuft  (figs.  120,  125),  the  branches  of  which 
elongate  and  then  divide  again,  forming  a larger  tuft  (figs.  121,122). 
The  first  interwoven  branches  form  a short  pedicel.  This  cuplike 
structure  may  be  regarded  as  the  primordium  of  the  sporodochium 
(fig.  123),  from  which  a bed  of  short  conidiophores  is  formed. 
The  development  is  clearly  simple  meristogenous.  Other  larger 
bases  are  quite  often  formed  symphogenously.  Then  hyphal 
branches  from  all  adjacent  mycelial  threads  interweave  and  anasto- 
mose, forming  a black  mass  of  sclerotial  character  from  which 
hyphae  arise  and  interweave  into  a cuplike  bed  from  which  conidio- 
phores develop. 

Volutella  circinans  (Berk.)  Stevens  and  True;  from  a white 
globe  onion  ( Allium  cepa  L.)  at  Urbana,  Illinois,  September  1917. 

Primordia  arise  by  either  of  2 methods,  simple  meristogenous 
(fig.  126)  or  symphogenous  (figs.  128-130).  In  most  instances  a 
black  stroma-like  mass  of  interwoven  hyphae  is  formed  symphoge- 
nously (figs.  130, 13 1),  from  which  the  sporodochium  later  develops. 
Setae  may  be  found  arising  as  hyphal  branches  (fig.  127). 

Volutella  is  very  similar  to  Colletotrichum  and  Gloeosporium  in 
the  origin  of  the  sporing  bodies;  the  meristogenous  and  sym- 
phogenous methods  are  both  found.  The  principal  distinction 
is  in  the  formation  of  a more  compact  and  usually  larger  base  or 
subicle  upon  which  the  sporodochium  is  produced.  The  origin 
of  this  subicle  if  it  is  simple  is  usually  meristogenous,  but  if  a 
complex  subicle  is  formed  it  arises  symphogenously  by  the  inter- 
weaving of  numerous  hyphal  branches. 

Epicoccum  Link 

Epicoccum,  species  indet. ; isolated  from  a plate  culture  in  which 
it  appeared  as  a contamination  in  October  1917. 

The  sporing  body  of  this  fungus  arises  from  2 or  more  closely 
lying  hyphae  which  produce  erect  branches  from  a rather  localized 
area.  Two  or  more  such  hyphae  arise  which  branch  in  turn  near 
their  tips.  These  form  a spreading  tuft  of  conidiophores  each  bear- 
ing a conidium  at  its  end.  This  is  a simple  form  of  sporodochium 
(fig.  132).  The  development  is  compound  meristogenous. 


250 


BOTANICAL  GAZETTE 


[OCTOBER 


Pycnidial  stage  oe  Meliola(?)  camelliae  (Catt.)  Sacc. 

This  pycnidium  was  studied  from  herbarium  material  collected 
by  Dr.  F.  L.  Stevens  in  Porto  Rico.  The  fungus,  which  usually 
is  reported  as  M.  camelliae  and  is  perhaps  better  known  as  “ sooty 
mold”  (48),  is  plainly  not  a true  Meliola,  as  the  genus  is  limited  by 
recent  writers  (16,  40),  and  the  position  of  its  ascigerous  stage  has 
not  been  definitely  determined. 

A small  pycnidium  arises  from  a single  cell  of  the  main  hypha 
or  a single  cell  of  a hyphal  branch.  The  initial  cell  is  usually  an 
intermediate  cell,  but  it  may  be  a terminal  one.  In  either  case  it 
divides  by  transverse  and  diagonal  walls  into  2,  then  4 cells 
(fig.  133),  and  by  swelling  and  dividing  becomes  an  elliptical, 
finely  reticulated,  dark  brown  body  (figs.  134-137).  The  mode  is 
simple  meristogenous. 

These  observations  do  not  essentially  disagree  with  the  descrip- 
tions as  given  by  Zopf  (53)  and  Tulasne  (43),  who  studied  early 
stages  of  the  development  of  the  pycnidium  of  the  sooty  molds. 

Discussion 

Two  main  methods  of  origin  and  early  development  are  found 
in  pycnidial  formation,  namely  meristogenous  and  symphogenous. 
The  meristogenous  method  resolves  itself  into  2 modes,  simple 
(figs.  1,  2,  4,  5)  and  compound  (figs.  18,  22,  37).  In  the  simple 
mode  the  pycnidium  develops  from  a single  cell  or  a few  adjacent 
cells  of  a single  hypha.  In  the  compound  mode  adjacent  cells 
of  2 or  more  contiguous  hyphae  divide,  swell,  and  sometimes 
branch,  all  of  these  then  anastomosing  freely  to  form  a pseudo- 
parenchymatous  mass.  Variations  of  these  2 modes  are  found  in 
Macrophoma  citrulli  (figs.  39,  43,  47),  Coniothyrium  pyriana 
(figs.  69-71),  Septoria  polygonorum  (figs.  76,  77),  Sphaeronaema 
fimbriatum  (figs.  50-52),  and  Sphaeronaemella fragariae  (figs.  82-85). 

The  symphogenous  method  (figs.  48,  49,  54,  55)  is  less  often 
found  in  the  species  studied.  In  this  method  of  development, 
branching  hyphae  from  main  mycelial  threads  are  directed  toward 
a common  point,  loop  back,  and  interweave  to  form  a loose  network 
which  later  becomes  more  close.  The  hyphae  of  this  ball  anasto- 
mose into  a pseudoparenchymatous  mass  from  which  the  pycnidium 
develops. 


1919] 


KEMPTON — PYCNIDIUM 


251 


Table  I gives  the  species  and  the  methods  of  development 
found  in  each  of  the  pycnidium-forming  species.  Phoma  her- 
barum,  Phoma  pirina , Phoma  from  clover,  Phoma  from  grape, 
Sphaeronaema  fimbriatum,  Coniothyrium  species  indet.,  Septoria 
helianthi,  Sphaeronaemella  fragariae,  and  a pycnidium  of  Meliola{  ?) 
camelliae  show  a simple  meristogenous  origin  and  development, 
and  other  methods  of  development  seldom  or  never  appear. 

TABLE  I 


Species 

Simple 

meristogenous 

Compound 

meristogenous 

Symphogenous 

Phoma  herbarum  West 

+ 





Phoma  destructiva  Plowr 

+ 

+ 

— 

Phoma  pirina  (Fries)  Cooke 

+ 

— 

Phoma  from  clover 

+ 

— 

— 

Phoma  from  grape , 

+ 

— 

— 

Phoma  cichorii  Passr 

+ 

+ 

— 

Macrophoma  citrulli  (B.  and  C.)  Berl.  and 
Vogl 

+ 

+ 

+ 

Sphaeronaema  fimbriatum  (E.  and  H.) 
Sacc 

+ 

_ 

_ 

Sphaeropsis  malorum  Pk 

— 

+ 

+ 

Sphaeropsis  citricola  McAlpine 

+ 

+ 

— 

.Coniothyrium  pyriana  (Sacc.)  Shel 

+ 

+ 

— 

Coniothyrium,  species  indet 

+ 

— 

— 

Septoria  polygonorum  Desm 

+ 

+ 

+ 

Septoria  scrophulariae  Pk 

+ 

+ 

— 

Septoria  helianthi  E.  and  K 

+ 

— 

— 

Sphaeronaemella  fragariae  S.  and  P 

+ 

— 

— 

Pycnidium  of  Meliola  ( ?)  camelliae  (Catt.) 
Sacc 

+ 

- 

- 

In  Phoma  destructiva,  Phoma  cichorii,  Sphaeropsis  citricola, 
Coniothyrium  pyriana,  and  Septoria  scrophulariae  the  pycnidial 
primordia  arise  by  either  the  simple  or  compound  meristogenous 
modes,  the  simple  mode  being  the  more  common. 

Macro  phoma  citrulli,  Sphaeropsis  malorum , and  Septoria  poly- 
gonorum  give  rise  to  their  pycnidial  primordia  by  either  the  sym- 
phogenous  or  meristogenous  methods.  In  Sphaeropsis  malorum 
the  symphogenous  method  is  the  main  one.  The  compound 
meristogenous  method  appears  occasionally.  In  Macro  phoma 
citrulli  the  simple  meristogenous  mode  prevails,  but  the  others  are 
often  found.  In  Septoria  polygonorum  the  compound  meristoge- 
nous mode  is  more  often  found,  although  a few  primordia  arise 
by  the  symphogenous  method,  and  occasionally  the  simple  meris- 
togenous mode  appears. 


252 


BOTANICAL  GAZETTE 


[OCTOBER 


Variations  of  these  3 modes  of  development  are  found.  No  2 
species  give  exactly  the  same  development.  In  symphogenous 
development  a few  branches  from  nearly  hyphal  strands  may  inter- 
weave near  their  ends,  or  intermingling  hyphae  may  loop  back, 
branch,  and  interweave  or  snarl  into  a knotlike  mass.  In  the 
simple  meristogenous  mode  the  origin  may  be  a single  cell  which 
swells  and  divides,  or  a number  of  cells  that  swell  and  divide 
simultaneously.  In  some  cases  branches  arising  from  the  dividing 
cells  anastomose  with  the  enlarging  mass.  In  other  cases  branches 
arise  from  more  distant  cells  of  the  same  strand  and  take  part  in 
the  development.  In  a few  instances  short  budlike  branches 
arise  from  a few  cells  of  a hyphal  strand,  enlarge,  divide  into  short 
cells,  intertwine,  and  anastomose  to  form  a pycnidium. 

Neither  have  the  acervuli-forming  fungi  in  the  Melanconiales 
been  studied  as  to  the  early  development  of  their  sporing  bodies, 
nor  has  the  origin  of  the  sporodochium  been  given  special  attention. 
Sherbakoff  (37),  in  studies  of  Fusarium , describes  a simple  type 
of  sporodochium  found  in  cultures.  Tulasne  (43) , Stoneman  (42) , 
Southworth  (38,  39),  Wolf  (50,  51),  and  others  figure  and  describe 
later  stages  of  the  development  of  acervuli,  and  the  later  develop- 
ment ofsporodochia  are  referred  to  in  the  literature,  but  the  subject 
is  considered  merely  incidentally. 

The  fungi  that  form  acervuli  and  sporodochia  may  be  classed 
according  to  the  manner  of  origin  and  development  of  the  primordia 
on  the  same  basis  as  the  pycnidia-forming  species. 

In  table  II  fungi  of  the  Melanconiales  and  Tuber culariaceae 
that  were  studied  are  listed,  indicating  the  method  or  methods 
of  development  of  the  primordia.  In  Gloeosporium  rufomaculans, 
Gloeosporium  musarum , and  Pestalozzia  guepini  the  primordia 
originate  by  the  symphogenous  method.  In  Colletotrichum  lage- 
narium  and  Volutella  circinans  the  symphogenous  method  prevails, 
although  the  simple  meristogenous  mode  occurs  occasionally.  The 
compound  meristogenous  mode  is  well  exemplified  by  Pestalozzia 
palmarum,  Pestalozzia  from  peony  and  from  maple.  Epicoccum 
and  Pestalozzia  from  maple  have  only  the  compound  meristogenous 
mode.  The  simple  meristogenous  method  of  development  appears 
in  Colletotrichum  lagenarium,  Pestalozzia  palmarum , Pestalozzia 


1919] 


KEMPTON — PYCNIDIUM 


253 


from  peony,  Volutella  fructi,  and  Volutella  circinans;  it  also  is  at 
times  observed  in  the  development  of  isolated  sporodochia  of 
Patellina  fragariae.  This  mode  is  more  seldom  found  than  either 
the  compound  meristogenous  or  symphogenous  method  in  the 
development  of  acervuli  and  sporodochia. 


TABLE  II 


Species 

Simple 

meristogenous 

Compound 

meristogenous 

Symphogenous 

Gloeosporium  rufomaculans  (Berk.)  Thiim. 

— 

— 

+ 

Gloeosporium  musarum  C.  and  M 

Colletotrichum  lagenarium  (Pers.)  E. 

— 

— 

+ 

andH 

+ 

+ 

+ 

Pestalozzia  palmarum  Cke 

+ 

+ 

— 

Pestalozzia  guepini  Desm 

— 

— 

+ 

Pestalozzia  from  peony 

+ 

+ 

— 

Pestalozzia  from  maple 

— 

+ 

— 

Patellina  fragariae  S.  and  P '. . . 

+ , 

+ 

— 

Patellina  from  quince 

— 

+ 

— 

Volutella  fructi  S.  and  H 

+ 

— 

+ 

Volutella  circinans  (Berk.)  S.  and  T 

+ 

— 

+ 

Epicoccum,  species  indet 

— 

+ 

— 

The  species  of  Pestalozzia  studied  present  a type  of  sporing 
structure  which  is  in  need  of  further  investigation  in  other  genera 
and  species.  From  the  mature  structure  it  has  been  classed  as  an 
acervulus,  but  from  its  origin  and  development  it  is  not  a true 
acervulus,  for  it  arises  as  a pycnidium  and  opens  to  form  an  acer- 
vulus when  mature.  This  may  be  called  a pseudo-acervulus. 

According  to  Potebnia  (30)  and  Diedicke  (10),  some  species 
of  Septoria  and  Ascochyta  have  open-topped  sporing  bodies 
arising  by  the  interweaving  of  hyphae  to  form  a bed  from  which 
arises  a peridium  partially  surrounding  the  inner  sporing  surface. 
Such  a structure  is  designated  by  Potebnia  as  a pseudo-pycnidium. 

Study  of  the  origin  and  development  of  the  sporing  bodies  of 
the  many  genera  and  species  of  the  Sphaeropsidales  and  Melan- 
coniales  which  have  not  yet  been  investigated  will  no  doubt  add  to 
these  2 types. 

In  the  pycnidia-bearing  fungi  studied  the  meristogenous  method 
of  development  is  the  more  prevalent,  the  symphogenous  type 
seldom  appearing.  In  species  forming  acervuli  and  sporodochia, 


254 


BOTANICAL  GAZETTE 


[OCTOBER 


the  tendency  is  toward  the  more  complex  methods,  especially  if 
Pestalozzia  be  regarded  as  belonging  to  the  Sphaeropsidales.  As 
was  to  be  expected,  in  the  pycnidial  development  no  sexual  organs, 
ascogenous  hyphae,  or  nuclear  fusions  were  observed. 

Summary 

1 . Pycnidia  originate  and  develop  by  2 main  methods,  namely, 
meristogenous  and  symphogenous. 

2.  The  meristogenous  method  resolves  itself  into  2 modes, 
simple  and  compound. 

3.  Variations  of  the  meristogenous  method  are  found,  for 
example,  in  Coniothyrium  pyriana  and  Sphaeronaemella  fragariae. 

4.  The  symphogenous  method  is  less  often  found  and  is  variable. 

5.  Acervuli  arise  in  the  same  manner  as  do  pycnidia,  simple 
acervuli  by  the  simple  meristogenous  mode,  and  complex  ones 
usually  by  the  compound  meristogenous  or  symphogenous  method. 

6.  Complex  subicles  usually  arise  symphogenously,  although 
they  may  arise  by  the  compound  meristogenous  mode. 

7.  Simple  sporodochia,  especially  those  appearing  on  single 
isolated  strands,  originate  by  the  simple  meristogenous  method. 

8.  Complex  sporodochia,  with  a large  base  or  subicle,  usually 
arise  either  by  the  compound  meristogenous  mode  or  symphoge- 
nously. 

9.  The  pseudo-acervulus  of  the  species  of  Pestalozzia  studied 
arises  and  develops  as  a pycnidium  which  breaks  open  and  appears 
like  an  acervulus. 

10.  The  simple  meristogenous  development  is  the  more  often 
found  in  the  Sphaeropsidales,  while  the  compound  meristogenous 
and  symphogenous  modes  are  the  more  usual  in  the  Melanconiales 
and  Tuber culariaceae. 

I gratefully  acknowledge  the  very  helpful  guidance  of  Dr.  F.  L. 
Stevens  throughout  the  preparation  of  this  thesis,  and  I also 
wish  to  express  my  appreciation  of  suggestions  and  encouragement 
by  Professor  William  Trelease.  Thanks  are  also,  due  others 
who  have  kindly  furnished  material  or  suggestions. 

University  of  Illinois 
Urbana,  III. 


KEMPTON — PY^CNIDIUM 


255 


1919] 


LITERATURE  CITED 

1.  Anderson,  P.  J.,  The  morphology  and  life  history  of  the  chestnut  blight 
fungus.  Commission  for  investigation  and  control  of  chestnut  tree  blight 
in  Penn.  Bull.  7.  1913. 

2.  Anderson,  P.  J.,  and  Rankin,  W.  H.,  Endothia  canker  of  chestnut. 
N.Y.  (Cornell)  Agric.  Exp.  Sta.  Bull.  347.  1914. 

3.  Arnaud,  Gabriel,  Contribution  a l’etude  des  Fumagines.  Ann.  FEcole 
Nat.  d’Agric.  Montpellier.  II.  9:239.  1910. 

4.  Bainier,  G.,  and  Sartory,  A.,  Etude  d’une  espece  nouvelle  de  Pestalozzia. 
Annales  Mycol.  10:433.  1912. 

5.  Bauke,  Herman,  Beitrage  zur  Kenntnis  der  Pycniden.  I.  Nova  Acta 
Leop.  Carol.  Deutsch.  Akad.  38:443.  1876. 

6.  Brefeld,  O.,  Bot.  Unters.  fiber  Schimmelpilze.  4:122.  1881. 

7.  , Bot.  Unters.  a.d.  Gesammtgebeit  d.  Mykologie  9:  and  10:1891. 

8.  DeBary,  A.,  and  Woronin,  W.  W.,  Beitrage  zur  Morphologie  und  Physi- 
ologic der  Pilze.  3:1870. 

9.  DeBary,  A.,  Comparative  morphology  and  biology  of  the  Fungi,  Myce- 
tozoa,  and  Bacteria.  1884.  Engl.  transl.  1887. 

10.  Diedicke,  H.,  Die  Abteilung  Hyalodidymae  der  Sphaerioideen.  Annales 
Mycol.  10:135.  1912. 

11.  Edgerton,  C.  W.,  The  physiology  and  development  of  some  anthracnoses. 
Bot.  Gaz.  45:367-408.  1908. 

12.  , The  new  fig  diseases.  Phytopath.  1:13.  1911. 

13.  Eld  am,  Dr.,  Uber  Pycniden.  Beibl.  Tagebl.  49  Versamml.  Deutsch. 
Naturforsch.  1876;  rev.  in  Just’s  Bot.  Jahresber.  4:176.  1876. 

14.  , Uber  Pycniden.  Bot.  Zeit.  35:60.  1877. 

15.  Fischer,  Ed.,  Beitrag  zur  Kenntnis  der  Gattung  Graphiola.  Bot.  Zeit. 
41:745.  1883. 

16.  Gaillard,  A.,  Le  genre  Meliola.  Paris.  1892. 

17.  Gibelli,  G.,  and  Griffini,  L.,  Sul  polimorfismo  della  Pleospora  herbarum 
Tul.  Ricerche  Lab.  Bot.  Crittogamica  Pavia;  rev.  in  Just’s  Bot.  Jahresber. 
1:125.  1873. 

18.  Halsted,  B.  D.,  and  Fairchild,  D.  G.,  Sweet  potato  black  rot.  Jour. 
Mycol.  7:1-11.  1891. 

19.  Hesler,  L.  R.,  Black  rot,  leaf  spot,  and  canker  of  pomaceous  fruits. 
N.Y.  (Cornell)  Agric.  Exp.  Sta.  Bull.  379.  1916. 

20.  Higgins,  B.  B.,  Contribution  to  the  life  history  and  physiology  of  Cylin- 
drosporium  on  stone  fruits.  Amer.  Jour.  Bot.  1 : 145.  1914. 

21.  , Life  history  of  a new  species  of  Sphaerella.  Mycol.  Centralbl. 

4:187.  1914. 

22.  Jamieson,  Clara  O.,  Phoma  destructiva,  the  cause  of  a fruit  rot  of  the 
tomato.  Jour.  Agric.  Research  4:1.  1915. 

23.  Klebahn,  von  H.,  Beitrage  zur  Kenntnis  der  Fungi  Imperfecti.  I— II. 
Mycol.  Centralbl.  3:49,  97.  1913. 


[OCTOBER 


256  BOTANICAL  GAZETTE 

24.  Leininger,  H.,  Zur  Morphologic  und  Physiologic  der  Fortpflanzung  von 
Pestalozzia  palmar um  Cooke.  Centralbl.  Bakt.  II.  29:3.  1911. 

25.  Levin,  Ezra,  The  leaf  spot  disease  of  tomato.  Mich.  Agric.  Col.  Exp. 
Sta.  Tech.  Bull.  25.  1916. 

26.  Mercer,  W.  B.,  On  the  morphology  and  development  of  Phoma  Richardiae 
Mycol.  Centralbl.  2:244.  1913. 

27.  Nichols,  Mary  A.,  The  morphology  and  development  of  certain  Pyreno- 
mycetous  Fungi.  Bot.  Gaz.  22:301.  1896. 

28.  Pierce,  Newton  B.,  A disease  of  almond  trees.  Jour.  Mycol.  7:66. 
1892. 

29.  Planchon,  Louis,  Influence  des  milieux  sur  les  Dematiees.  Ann.  Sci. 
Nat.  Bot.  VIII.  11 : 1.  1900. 

30.  Potebnia,  A.,  Beitrage  zur  Micromycetonflora  Mittel-Russlands.  Annales 
Mycol.  8:42-93.  1910. 

31.  Reddick,  Donald,  The  black  rot  disease  of  grapes.  N.Y.  (Cornell) 
Agric.  Exp.  Sta.  Bull.  293.  1911. 

32.  Saccardo,  P.  A.,  Sylloge  Fungorum. 

33.  Schnegg,  H.,  Zur  Entwicklungsgeschichte  und  Biologie  der  Pykniden, 
sowie  der  Schlingenmycelien  und  Hyphenknauel.  Centralbl.  Bakt.  II. 
43:326.  1915. 

34.  Schostakowitsch,  W.,  Uber  die  Bedingungen  der  Conidienbildung  bei 
Russtbaupilzen.  Flora  81:362.  1895. 

35.  Shear,  C.  L.,  Cultural  characters  of  the  chestnut  blight  fungus  and  its 
near  relatives.  U.S.  Dept.  Agric.  Bur.  PI.  Ind.  Circ.  131.  1913. 

36.  Shear,  C.  L.,  and  Wood,  Anna  K.,  Studies  of  fungous  parasites  belonging 
to  the  genus  Glomerella.  U.S.  Dept.  Agric.  Bur.  PI.  Ind.  Bull.  no.  252. 
I9i3- 

37.  Sherbakoff,  C.  D.,  Fusaria  of  potatoes.  N.Y.  (Cornell)  Agric.  Exper. 
Sta.  Mem.  no.  6.  1915. 

38.  Southworth,  E.  A.,  Anthracnose  of  cotton.  Jour.  Mycol.  6:100-105. 
1891. 

39.  , Ripe  rot  of  grapes  and  apples.  Jour.  Mycol.  6:164.  1891. 

40.  Stevens,  F.  L.,  The  genus  Meliola  in  Porto  Rico.  III.  Biol.  Monographs. 
2:7.  1916. 

41.  Stewart,  V.  B.,  The  leaf  blotch  disease  of  horse  chestnut.  Phytopath. 
6:5-19.  1916. 

42.  Stoneman,  Bertha,  A comparative  study  of  the  development  of  some 
anthracnoses.  Bot.  Gaz.  26:69-120.  1898. 

43.  Tulasne,  L.  R.  and  C.,  Selecta  Fungorum  Carpologia.  2:1863. 

44.  Van  der  Bijl,  Paul  A.,  A study  of  the  “dry-rot”  disease  of  maize  caused 
by  Diplodia  zeae.  Dept.  Agric.  Div.  Bot.  and  PI.  Path.  Sci.  Bull.  no.  7. 
1916.  Pretoria. 

45.  Voges,  E.,  Uber  die  Pilzgattung  Hendersonia  Berk.  Bot.  Zeit.  68:87. 
1910. 


1919] 


KEMPTON — PYCNIDIUM 


257 


6.  von  Tavel,  Franz,  Beitrage  zur  Entwickelungsgeschichte  der  Pyre- 
nomyceten.  Bot.  Zeit.  44:825.  1886;  transl.  in  Jour.  Mycol.  5 = 53-  1889. 

47.  , Vergleichende  Morphologie  der  Pilze.  Jena.  1892. 

48.  Webber,  Herbert  J.,  Sooty  mold  of  the  orange  and  its  treatment. 
U.S.  Dept.  Agric.  Div.  Veg.  Phys.  and  Path.  Bull.  13.  1897. 

49.  Wenner,  John  T.,  A contribution  to  the  morphology  and  life  history  of 
Pestalozzia  funerea  D esm . Phytopath .4:375.  1914. 

50.  Wole,  Fredrick  A.,  The  perfect  stage  of  Actinonema  rosae.  Bot.  Gaz. 
54:218.  1912. 

51.  , Some  fungous  diseases  of  the  prickly  pear,  Opuntia  Lindheimeri 

Engelm.  Ann.  Mycologici.  10:113.  1912. 

52.  Zope,  W.,  Die  Pilze,  in  Schenk’s  Handbuch  der  Botanik.  4:1890. 

53.  , Die  Conidien  Friichte  von  Fumago.  Nova  Acta  Leop.  Carol. 

Deutsch.  Akad.  40:1878. 

EXPLANATION  OF  PLATES  XVII-XXII 

The  drawings  were  made  with  a Leitz  camera  lucida  and  a Leitz  one- 
twelfth  oil  immersion  lens  or  a no.  6 objective.  The  scale  appears  on  the 
plates. 

PLATE  XVII 

Phoma 

Fig.  1. — P.  herbarum  West:  4-celled  stage  of  pycnidial  primordium  of 
simple  meristogenous  origin. 

Fig.  2. — Slightly  later  stage. 

Fig.  3. — Stage  similar  to  fig.  2. 

Fig.  4. — Young  pycnidium  with  fight  colored  rostrum  where  ostiole  will 
form. 

Fig.  5. — Mature  pycnidium  and  spores  formed  by  simple  meristogenous 
development. 

Fig.  6. — P.  pinna,  (Fries)  Cooke:  few-celled  stage;  simple  meristogenous 
origin. 

Fig.  7. — Slightly  later  stage. 

Fig.  8. — Many-celled  pseudoparenchymatous  stage  with  branches  protrud- 
ing from  mass. 

Fig.  9. — Irregular  mass  from  which  pycnidium  develops. 

Figs.  10,  11. — Few-celled  stages  in  origin  of  which  2 or  more  hyphae  are 
involved;  compound  meristogenous  origin. 

Fig.  12. — Similar  to  fig.  11,  but  slightly  older. 

Fig.  13. — Primordium  in  which  a 3-parted  hyphal  strand  is  involved. 

Figs.  14-16. — P.  destructiva  Plowr.:  beginning  stages  in  pycnidial  develop- 
ment; simple  meristogenous  origin. 

Fig.  17. — Slightly  later  stage. 

Figs.  18,  19. — Compound  meristogenous  development  in  which  2 or  more 
hyphae  are  involved. 


258 


BOTANICAL  GAZETTE 


[OCTOBER 


Fig.  20. — Development  near  end  of  hypha  with  branches  budding  from 
mass. 

Fig.  21. — Irregular  meristogenous  development. 

Fig.  22. — Typical  compound  meristogenous  development  with  3 parallel 
hyphae  involved. 

PLATE  XV III 

Figs.  23,  24. — Phoma  from  clover:  beginnings  of  pycnidia. 

Fig.  25. — Slightly  older  stage  with  a few  short  budding  branches. 

Figs.  26,  27. — Later  stages  with  one  end  enlarging  slightly. 

Fig.  28. — Phoma  from  grape:  mycelial  threads  with  different  stages  of 
pycnidial  development. 

Fig.  29. — Beginning  stage:  simple  meristogenous. 

Figs.  30-32. — Later  stages. 

Fig.  33. — Mature  pycnidium. 

Fig.  34. — P.  cichorii  Passr.:  early  stage  in  development;  short  cells  formed 
which  divide  and  branch. 

Fig.  35. — Early  stage  in  which  is  much  branching. 

Fig.  36. — Medium  stage  in  simple  meristogenous  development. 

Fig.  37. — Typical  compound  meristogenous  development. 

Macrophoma 

Fig.  38. — M.  citrulli  (B.  and  C.)  Berl.  and  Vogl.:  2-celled  stage  in  origin 
of  pycnidium,  from  drop  culture;  simple  meristogenous  development. 

Fig.  39. — Same  12  hours  later. 

Figs.  40,  41. — Early  stages  of  other  pycnidia,  from  drop  culture;  slight 
variation  from  simple  meristogenous  type  in  that  many  branches  are  involved. 

Figs.  42,  43. — Early  stages  in  which  much  branching  takes  place;  drop 
culture. 

Figs.  44,  45. — Early  stages  from  Petri  dish  culture. 

Figs.  46,  47. — Later  stages. 

PLATE  XIX 

Fig.  48. — M.  citrulli  (B.  and  C.)  Berl.  and  Vogl.:  symphogenous  develop- 
ment in  which  branches  from  a number  of  main  strands  interweave. 

Fig.  49. — Later  stage  in  which  a winding  of  the  hyphae  and  cell  division 
have  taken  place  forming  a pseudoparenchymatous  mass. 

Sph&eronaema 

Figs.  50-52. — S.fimbriatum  (E.  and  H.)  Sacc.:  early  stages  of  pycnidium 
in  which  a hypha  coils,  branches,  and  divides  to  form  knotlike  mass. 

Sphaeropsis 

Fig.  53. — S.  malorum  Pk.:  Early  stage  in  symphogenous  development  in 
which  branches  a,  b,  c interweave  near  their  ends  to  form  a ball. 

Fig.  54. — Interwoven  hyphae  in  early  stage  of  symphogenous  develop- 
ment. 


IQI91 


KEMPTON—P  YCNIDIUM 


259 


Fig.  55. — Slightly  later  stage. 

Figs.  56,  57. — S.  citricola  McAlp.:  very  early  stages  in  origin  of  simple 
meristogenous  development  of  pycnidia. 

Figs.  58,  59. — Slightly  later  stages. 

Figs.  60-63. — Later  stages  with  short  hyphae  branching  from  masses. 

Figs.  64-66. — Unusual  examples  of  developments  in  which  more  than  one 
hypha  is  involved;  compound  meristogenous. 

Coniothyrium 

Figs.  67,  68. — C.  pyriana  (Sacc.)  Shel.:  early  stages  in  development. 

Figs.  69,  70. — Later  stages  in  which  numerous  branches  from  dividing 
mass  are  involved. 

Fig.  71. — Pseudoparenchymatous  mass  from  which  a pycnidium  arises. 

PLATE  XX 

Fig.  72. — Coniothyrium  species  from  laboratory  air:  early  stage  showing 
short  cells  and  short  branches  as  origin. 

Fig.  73. — Slightly  later  stage  in  which  cells  and  branches  from  main  hypha 
divide  into  short  cells  and  anastomose. 

Fig.  74. — Stage  slightly  more  developed  than  fig.  73 ; slight  variation  from 
simple  meristogenous  type. 

Septoria 

Fig.  75. — S.  polygonorum  Desm.:  beginning  stage  of  simple  meristogenous 
development. 

Fig.  76. — Development  in  which  original  hypha  and  numerous  branches 
are  involved. 

Fig.  77. — Pseudoparenchymatous  primordial  mass  formed  by  symphoge- 
nous  method. 

Figs.  78,  79. — S . scrophulariae  Pk.:  early  stages  in  compound  meristo- 
genous development. 

Fig.  80. — S.  helianthi  E.  and  K.:  early  stage  in  beginning  of  simple 
meristogenous  development. 

Fig.  81.  Later  stage. 

Sphaeronaemella 

Fig.  82. — S.  fragariae  S.  and  P.:  early  stage  of  simple  meristogenous 
development. 

Fig.  83. — Later  stage  in  which  branches  and  original  hypha  have  anasto- 
mosed to  form  a mass  on  one  side  of  main  strand. 

Fig.  84. — Later  stage  in  which  mass  surrounds  main  strand. 

Fig.  85. — Late  stage  which  has  developed  by  a winding  and  dividing  of 
hyphal  branches  from  a few  cells  upon  one  side  of  main  strand. 

Gloeosporium 

Fig.  86. — G.  rufomaculans  (Berk.)  Thiim.:  early  stage  of  meristogenous 
development;  this  method  rarely  occurs. 


26o 


BOTANICAL  GAZETTE 


[OCTOBER 


Fig.  87. — Side  view  of  an  acervulus  formed  by  symphogenous  method: 
compressed  so  that  cushion-like  bed  of  conidiophores  is  pulled  away  from  basal 
hypha. 

Fig.  88. — G.  musarum  C.  and  M.:  top  view  of  partially  developed  acer- 
vulus; development  symphogenous. 

Colletotrichum 

Fig.  89. — C.  lagenarium  (Pers.)  E.  and  H.:  very  early  stage  in  which 
acervulus  originates  in  a few  short  branches  from  a single  hypha. 

Fig.  90. — Numerous  budding  branches  from  a few  cells  of  one  hypha 
forming  beginning  of  an  acervulus;  simple  meristogenous. 

Fig.  91. — Early  stage  in  development  of  acervulus. 

Fig.  92. — Primordium  in  which  a few  branches  are  involved. 

Fig.  93. — Early  stage  in  symphogenous  development:  hyphal  branches 
loop  and  interweave  in  this  mode. 

Fig.  94. — Same  as  fig.  93,  24  hours  later. 

Fig.  95. — Beginning  stage  of  symphogenous  development. 

Fig.  96. — Later  stage. 


PLATE  XXI 
Pestalozzia 

Fig.  97. — P.  palmarum  Cke. : a,  very  early  stage  in  meristogenous  develop- 
ment, a few  cells  divided  and  swelling;  b,  later  stage. 

Figs.  98,  99. — Pycnidia  with  young  spores  developed  within. 

Fig.  ioo. — Primordium  of  compound  meristogenous  origin. 

Fig.  ioi. — Young  pycnidium  at  stage  just  before  opening. 

Fig.  102. — Pycnidium  opening  and  extruding  spores:  following  this  stage 
cuplike  interior  formed,  longer  conidiophores  develop,  and  body  becomes  a 
pseudo-acervulus . 

Figs.  103,  104. — P.  guepini  Desm. : early  stages  in  symphogenous  develop- 
ment. 

Fig.  105. — Later  stage;  pycnidia  of  this  species  form  spores  within  and 
later  break  open  as  pseudo-acervuli. 

Fig.  106. — Pestalozzia  from  peony:  meristogenously  developed  pycnidial 
mass. 

Fig.  107. — Early  stage  in  symphogenous  development. 

Fig.  108. — Later  stage. 

Fig.  109. — Pycnidium  which  has  opened,  surface  view. 

Fig.  no. — Pestalozzia  from  maple:  compound  meristogenous  develop- 
ment from  a number  of  parallel  hyphae. 

Fig.  iii. — Later  stage. 

Fig.  1 1 2. — Young  pycnidium  breaking  open  on  one  side:  spores  show 
within. 


BOTANICAL  GAZETTE , LXVIII 


PLATE  XVII 


KEMPTON  on  PYCNIDIUM 


BOTANICAL  GAZETTE , LXVIII 


PLATE  XVIII 


KEMPTON  on  PYCNIDIUM 


BOTANICAL  GAZETTE , LXVIII 


PLATE  XIX 


KEMPTON  on  PYCNIDIUM 


BOTANICAL  GAZETTE , LXVIII 


PLATE  XX 


KEMPTON  on  PYCNIDIUM 


BOTANICAL  GAZETTE , LXVIII  PLATE  XXI 


KEMPTON  on  PYCNIDIUM 


BOTANICAL  GAZETTE , LXVIII 


PLATE  XXII 


KEMPTON  on  PYCNIDIUM 


KEMPTON — PYCNIDIUM 


261 


1919] 

PLATE  XXII 

Patellinia 

Fig.  1 13. — P.  fragariae  S.  and  P.:  single  strand,  with  characteristic 
branching,  from  sporogenous  area. 

Fig.  1 14. — Compound  meristogenously  developed  sporodochium  produced 
from  a number  of  hyphae,  as  fig.  113. 

Fig.  115. — Simple  meristogenous  development  with  branches  arising  from 
a few  cells. 

Fig.  1 16. — Later  stage  in  simple  meristogenous  development. 

Fig.  1 1 7. — Simple,  meristogenously  developed,  mature  sporodochium. 

Fig.  1 18. — Pestalozzia  from  quince:  sporodochium  of  compound  meristo- 
genous development;  spore  bearing  area  develops  from  cuplike  top. 

Fig.  1 19. — Another  view  of  sporodochium  similar  to  fig.  118. 

Volutella 

Fig.  120. — V . fructi  S.  and  H.:  very  early  stage  in  simple  meristogenous 
origin  of  a sporodochium;  few  cells  branch  to  form  base. 

Fig.  1 21. — Slightly  later  stage. 

Fig.  122. — Medium  stage. 

Fig.  123. — Fully  developed  base  or  subicle. 

Fig.  124. — Same  as  fig.  120:  smaller  hypha. 

Fig.  125. — Later  stage  than  fig.  124. 

Fig.  126. — V.  circinans  Stevens  and  True:  simple  meristogenous  origin 
of  subicle  in  which  a cell  swells  and  branches  by  budding. 

Fig.  127. — Hypha  and  branches:  one  branch  has  developed  into  a seta. 

Fig.  128. — Beginning  of  symphogenous  development  of  a subicle. 

Fig.  129. — Later  stage. 

Fig.  130. — Many  branches  interweaving  to  form  a subicle. 

Fig.  1 3 1. —Complex  symphogenously  developed  subicle. 

Epicoccum 

Fig.  132. — Epicoccum , species  indet.:  compound  meristogenous  develop- 
ment of  simple  sporodochium  with  young  spores. 

Meliola(  ?) 

Fig.  133. — Pycnidium  with  M.(  ?)  camelliae:  4-cell  stage  developed  from 
single  cell  within  a hyphal  branch. 

Fig.  134. — Many-celled  stage  apparently  developed  from  end  cell  of 
hypha. 

Fig.  135. — Mature  pycnidium  developed  from  single  cell  within  hypha. 

Fig.  136. — Same  as  fig.  135. 

Fig.  137. — Slightly  different  pycnidium  from  figs.  133,  135. 


VITA  OF  AUTHOR 


Forrest  Ell  wood  Kempton  was  born  near  Centerville,  Indiana, 
October  5,  1883;  attended  Centerville  High  School,  graduating 
in  1902.  Graduated  from  Earlham  College,  Richmond,  Indiana, 
with  the  degree  of  Bachelor  of  Science  in  1906;  taught  in  schools 
of  Wayne  County,  Indiana,  1906-10;  was  farm  manager  and 
operator  1910-n,  and  taught  in  the  public  schools  /i9ii-i2.  He 
entered  the  University  of  Wisconsin  for  graduate  work  in  Botany 
and  Plant  Pathology  in  1912,  taking  the  degree  of  Master  of  Science 
in  Botany  in  June,  1913.  He  was  acting  Professor  of  Biology  at 
Illinois  College,  Jacksonville,  Illinois,  1 913-14.  At  the  beginning 
of  the  university  year  1914  he  became  an  Assistant  in  Botany  at 
the  University  of  Illinois,  continuing  graduate  work.  In  February, 
1917,  he  accepted  a position  as  Plant  Pathologist  in  Smelter  Smoke 
Investigation  for  the  St.  Louis  Smelting  & Refining  Company  at 
Collinsville,  Illinois,  and  returned  to  the  University  of  Illinois 
in  September,  1918,  as  an  Assistant  in  Botany  and  graduate  student. 


262 


I 


